Perl copying data from one DB to another - mysql

Question

I have a particular problem where I need to copy data from certain tables from one DB to another DB, both running in the same instance.
It is important to note that table structures in both DBs are identical, I can't use mysqldump because I need to copy only few tables.
Since the table structure is identical, I don't know, how can I do an equivalent of select * from one DB and insert * into another DB, I really don't want to use column names, because I want that table structures are identical.
Is it correct to assume that it will be done in two steps, step 1 to select records from one DB and step two to return into another DB?

Answer 1

You can use the INSERT INTO ... SELECT construct. If the column names are the same that is very easy, because you can just omit them alltogether.
INSERT INTO new SELECT * FROM old;
From Perl you'd run that with DBI.
use strict;
use warnings;
use DBI;
my $dbh = DBI->connect($dsn) or die DBI->errstr;
my #tables = qw(
foo
bar
customers
);
foreach my $table ( #tables ) {
$dbh->do("INSERT INTO new_db.$table SELECT * FROM old_db.$table")
or die $dbh->errstr;
}

Answer 2

With mysqldump you can copy only somes tables:
mysqldump -u... -p... mydb t1 t2 t3
But you can use ugly thinks like :
my $sth=$dbh->prepare("select * from table");
while (($row = $sth->fetchrow_arrayref))
{
my $i;
for($i=0;$i<=$#$row;$i++)
{
$row->[$i] = $dbh->quote($row->[$i]);
}
$dbh2->do("insert into table values (". join(',', #$row) . ")");
}
$sth->finish();
I'm not sure that thinks like that works in all case.